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Finding the Fourth Proportional to 636.76, 879 and 400.91

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Solution

The fourth proportional to 636.76, 879 and 400.91 is: 553.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.76 : 879 = 400.91 : x
  2. Step 2: Convert to fraction form
    636.76/879 = 400.91/x
  3. Step 3: Cross multiply
    636.76x = 879 × 400.91
  4. Step 4: Simplify right side
    636.76x = 352,399.89
  5. Step 5: Solve for x
    x = 352,399.89/636.76
  6. Step 6: Final answer
    x = 553.43

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.